Messages in this thread Patch in this message | | | From | Davidlohr Bueso <> | Subject | [PATCH 5/8] locking/mutex: Introduce ww_mutex_set_context_slowpath | Date | Sun, 28 Dec 2014 01:11:20 -0800 |
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... which is equivalent to the fastpath counter part. This mainly allows getting some ww specific code out of generic mutex paths.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de> --- kernel/locking/mutex.c | 43 ++++++++++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 17 deletions(-)
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index caa3c9f..5b6df69 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -155,7 +155,7 @@ static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww, */ static __always_inline void ww_mutex_set_context_fastpath(struct ww_mutex *lock, - struct ww_acquire_ctx *ctx) + struct ww_acquire_ctx *ctx) { unsigned long flags; struct mutex_waiter *cur; @@ -191,6 +191,30 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock, spin_unlock_mutex(&lock->base.wait_lock, flags); } +/* + * after acquiring lock in the slowpath or when we lost out in contested + * slowpath, set ctx and wake up any waiters so they can recheck. + * + * Callers must hold the mutex wait_lock. + */ +static __always_inline void +ww_mutex_set_context_slowpath(struct ww_mutex *lock, + struct ww_acquire_ctx *ctx) +{ + struct mutex_waiter *cur; + + ww_mutex_lock_acquired(lock, ctx); + lock->ctx = ctx; + + /* + * Give any possible sleeping processes the chance to wake up, + * so they can recheck if they have to back off. + */ + list_for_each_entry(cur, &lock->base.wait_list, list) { + debug_mutex_wake_waiter(lock->base, cur); + wake_up_process(cur->task); + } +} #ifdef CONFIG_MUTEX_SPIN_ON_OWNER /* @@ -576,23 +600,8 @@ skip_wait: if (ww_ctx) { struct ww_mutex *ww = container_of(lock, struct ww_mutex, base); - struct mutex_waiter *cur; - /* - * This branch gets optimized out for the common case, - * and is only important for ww_mutex_lock. - */ - ww_mutex_lock_acquired(ww, ww_ctx); - ww->ctx = ww_ctx; - - /* - * Give any possible sleeping processes the chance to wake up, - * so they can recheck if they have to back off. - */ - list_for_each_entry(cur, &lock->wait_list, list) { - debug_mutex_wake_waiter(lock, cur); - wake_up_process(cur->task); - } + ww_mutex_set_context_slowpath(ww, ww_ctx); } spin_unlock_mutex(&lock->wait_lock, flags); -- 2.1.2
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